def triangular_jiafayunsuan(a, b, c):
    c = a + b
    return   c
def triangular_jianfayunsuan(a, b, c):
    c = a - b
    return   c
def triangular_chengfafayunsuan(a, b, c):
    c = a * b 
    return   c
def triangular_chufayunsuan(a, b, c):
    if c == a / b and c ==a + a/b:
        return   c
